Justification:
Mainly a bycatch species taken by trawl and hook, although with some limited targeting, for its flesh and oil. Catches in Australia have been increasing in the last few years with relaxation of mercury laws and fishers looking for non-quota species in the South East Trawl Fishery. The quality of the catch data has improved recently but there are as yet no species specific trends in abundance or biomass available. Biomass estimates in New Zealand over a ten-year period show no evidence of a declining trend, although there may be problems of effort standardization. Research surveys on the New South Wales slope over a 20-year period have shown a decline from 15.7 kg/h to 1.4 kg/h for the related longsnout dogfish Deania quadrispinosa. While there are currently no quantitative data on population trends, the species has low productivity and increased targeting should be viewed with concern. However, the species is currently still abundant and a Near Threatened assessment cannot be justified. The situation should be monitored carefully.

A wide but patchy distribution in the eastern Atlantic (Iceland to Southern Africa, excluding the Mediterranean) and Pacific (Chile, Peru, Japan, southern Australia and New Zealand). In Australia, between Coffs Harbour (New South Wales) and Green Head (southern Westerna Australia), including Tasmania. Continental and insular slopes and outer shelves, usually in depths between 400 and 900 m but recorded from 70 to 1,450 m (Last and Stevens 1994, Long 1997).

On or near the bottom of the continental slope and abyssal plain in depths from 70 to 1,450 m. In Australia, catch rates are highest in the 600 to 1,100 m zone (Daley et al. 2002). There appears to be some size and sex segregation by depth. Pregnant females are rare in catches from most areas (0.8% of mature females in New South Wales (NSW) and Tasmania). The diet consists of fish, cephalopds and crustaceans; myctophids were common prey in Australia, South Africa, Namibia and in the north east Atlantic which suggests feeding at some height above the bottom (Mauchline and Gordon 1983, Yano 1991, Ebert et al. 1992, Daley et al. 2002). This may reduce their vulnerability to trawl gear.

Population parameters in Australia are as follows (Daley et al. 2002):

Length at 50% maturity in the north east Atlantic was 85 cm for males and 106 cm for females (Clarkeet al. 2002). Ageing work from the North Atlantic suggests maturity at 17 years for males and 25 years for females and a longevity of 35 years (Clarke et al. 2002).

Caght for its liver oil and flesh. The livers are high in squalene comprising about 70% by weight (Bakes et al. 1995). Catches in Australia have been increasing in the last few years with relaxation of mercury laws and fishers looking for non-quota species in the South East Trawl Fishery.

Taken by trawl, hook and gillnet both as a target and bycatch species for its liver oil and flesh. The livers are high in squalene comprising about 70% by weight (Bakes et al. 1995). Catch rates of up to 500 kg/h have been reported from Australia. Catches in Australia have been increasing in the last few years with relaxation of mercury laws and fishers looking for non-quota species in the South East Trawl Fishery. Research surveys on the NSW slope over a 20 year period have shown a decline from 15.7 kg/h to 1.4 kg/h for the related longsnout dogfish Deania quadrispinosa (Graham et al. 1997).